All Downloads are FREE. Search and download functionalities are using the official Maven repository.
Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
vendor.github.com.pion.rtcp.source_description.go Maven / Gradle / Ivy
package rtcp
import (
"encoding/binary"
"fmt"
)
// SDESType is the item type used in the RTCP SDES control packet.
type SDESType uint8
// RTP SDES item types registered with IANA. See: https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-5
const (
SDESEnd SDESType = iota // end of SDES list RFC 3550, 6.5
SDESCNAME // canonical name RFC 3550, 6.5.1
SDESName // user name RFC 3550, 6.5.2
SDESEmail // user's electronic mail address RFC 3550, 6.5.3
SDESPhone // user's phone number RFC 3550, 6.5.4
SDESLocation // geographic user location RFC 3550, 6.5.5
SDESTool // name of application or tool RFC 3550, 6.5.6
SDESNote // notice about the source RFC 3550, 6.5.7
SDESPrivate // private extensions RFC 3550, 6.5.8 (not implemented)
)
func (s SDESType) String() string {
switch s {
case SDESEnd:
return "END"
case SDESCNAME:
return "CNAME"
case SDESName:
return "NAME"
case SDESEmail:
return "EMAIL"
case SDESPhone:
return "PHONE"
case SDESLocation:
return "LOC"
case SDESTool:
return "TOOL"
case SDESNote:
return "NOTE"
case SDESPrivate:
return "PRIV"
default:
return string(s)
}
}
const (
sdesSourceLen = 4
sdesTypeLen = 1
sdesTypeOffset = 0
sdesOctetCountLen = 1
sdesOctetCountOffset = 1
sdesMaxOctetCount = (1 << 8) - 1
sdesTextOffset = 2
)
// A SourceDescription (SDES) packet describes the sources in an RTP stream.
type SourceDescription struct {
Chunks []SourceDescriptionChunk
}
// Marshal encodes the SourceDescription in binary
func (s SourceDescription) Marshal() ([]byte, error) {
/*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* header |V=2|P| SC | PT=SDES=202 | length |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* chunk | SSRC/CSRC_1 |
* 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* chunk | SSRC/CSRC_2 |
* 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*/
rawPacket := make([]byte, s.len())
packetBody := rawPacket[headerLength:]
chunkOffset := 0
for _, c := range s.Chunks {
data, err := c.Marshal()
if err != nil {
return nil, err
}
copy(packetBody[chunkOffset:], data)
chunkOffset += len(data)
}
if len(s.Chunks) > countMax {
return nil, errTooManyChunks
}
hData, err := s.Header().Marshal()
if err != nil {
return nil, err
}
copy(rawPacket, hData)
return rawPacket, nil
}
// Unmarshal decodes the SourceDescription from binary
func (s *SourceDescription) Unmarshal(rawPacket []byte) error {
/*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* header |V=2|P| SC | PT=SDES=202 | length |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* chunk | SSRC/CSRC_1 |
* 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* chunk | SSRC/CSRC_2 |
* 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*/
var h Header
if err := h.Unmarshal(rawPacket); err != nil {
return err
}
if h.Type != TypeSourceDescription {
return errWrongType
}
for i := headerLength; i < len(rawPacket); {
var chunk SourceDescriptionChunk
if err := chunk.Unmarshal(rawPacket[i:]); err != nil {
return err
}
s.Chunks = append(s.Chunks, chunk)
i += chunk.len()
}
if len(s.Chunks) != int(h.Count) {
return errInvalidHeader
}
return nil
}
func (s *SourceDescription) len() int {
chunksLength := 0
for _, c := range s.Chunks {
chunksLength += c.len()
}
return headerLength + chunksLength
}
// Header returns the Header associated with this packet.
func (s *SourceDescription) Header() Header {
return Header{
Count: uint8(len(s.Chunks)),
Type: TypeSourceDescription,
Length: uint16((s.len() / 4) - 1),
}
}
// A SourceDescriptionChunk contains items describing a single RTP source
type SourceDescriptionChunk struct {
// The source (ssrc) or contributing source (csrc) identifier this packet describes
Source uint32
Items []SourceDescriptionItem
}
// Marshal encodes the SourceDescriptionChunk in binary
func (s SourceDescriptionChunk) Marshal() ([]byte, error) {
/*
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* | SSRC/CSRC_1 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*/
rawPacket := make([]byte, sdesSourceLen)
binary.BigEndian.PutUint32(rawPacket, s.Source)
for _, it := range s.Items {
data, err := it.Marshal()
if err != nil {
return nil, err
}
rawPacket = append(rawPacket, data...)
}
// The list of items in each chunk MUST be terminated by one or more null octets
rawPacket = append(rawPacket, uint8(SDESEnd))
// additional null octets MUST be included if needed to pad until the next 32-bit boundary
rawPacket = append(rawPacket, make([]byte, getPadding(len(rawPacket)))...)
return rawPacket, nil
}
// Unmarshal decodes the SourceDescriptionChunk from binary
func (s *SourceDescriptionChunk) Unmarshal(rawPacket []byte) error {
/*
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
* | SSRC/CSRC_1 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SDES items |
* | ... |
* +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*/
if len(rawPacket) < (sdesSourceLen + sdesTypeLen) {
return errPacketTooShort
}
s.Source = binary.BigEndian.Uint32(rawPacket)
for i := 4; i < len(rawPacket); {
if pktType := SDESType(rawPacket[i]); pktType == SDESEnd {
return nil
}
var it SourceDescriptionItem
if err := it.Unmarshal(rawPacket[i:]); err != nil {
return err
}
s.Items = append(s.Items, it)
i += it.len()
}
return errPacketTooShort
}
func (s SourceDescriptionChunk) len() int {
len := sdesSourceLen
for _, it := range s.Items {
len += it.len()
}
len += sdesTypeLen // for terminating null octet
// align to 32-bit boundary
len += getPadding(len)
return len
}
// A SourceDescriptionItem is a part of a SourceDescription that describes a stream.
type SourceDescriptionItem struct {
// The type identifier for this item. eg, SDESCNAME for canonical name description.
//
// Type zero or SDESEnd is interpreted as the end of an item list and cannot be used.
Type SDESType
// Text is a unicode text blob associated with the item. Its meaning varies based on the item's Type.
Text string
}
func (s SourceDescriptionItem) len() int {
/*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | CNAME=1 | length | user and domain name ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
return sdesTypeLen + sdesOctetCountLen + len([]byte(s.Text))
}
// Marshal encodes the SourceDescriptionItem in binary
func (s SourceDescriptionItem) Marshal() ([]byte, error) {
/*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | CNAME=1 | length | user and domain name ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
if s.Type == SDESEnd {
return nil, errSDESMissingType
}
rawPacket := make([]byte, sdesTypeLen+sdesOctetCountLen)
rawPacket[sdesTypeOffset] = uint8(s.Type)
txtBytes := []byte(s.Text)
octetCount := len(txtBytes)
if octetCount > sdesMaxOctetCount {
return nil, errSDESTextTooLong
}
rawPacket[sdesOctetCountOffset] = uint8(octetCount)
rawPacket = append(rawPacket, txtBytes...)
return rawPacket, nil
}
// Unmarshal decodes the SourceDescriptionItem from binary
func (s *SourceDescriptionItem) Unmarshal(rawPacket []byte) error {
/*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | CNAME=1 | length | user and domain name ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
if len(rawPacket) < (sdesTypeLen + sdesOctetCountLen) {
return errPacketTooShort
}
s.Type = SDESType(rawPacket[sdesTypeOffset])
octetCount := int(rawPacket[sdesOctetCountOffset])
if sdesTextOffset+octetCount > len(rawPacket) {
return errPacketTooShort
}
txtBytes := rawPacket[sdesTextOffset : sdesTextOffset+octetCount]
s.Text = string(txtBytes)
return nil
}
// DestinationSSRC returns an array of SSRC values that this packet refers to.
func (s *SourceDescription) DestinationSSRC() []uint32 {
out := make([]uint32, len(s.Chunks))
for i, v := range s.Chunks {
out[i] = v.Source
}
return out
}
func (s *SourceDescription) String() string {
out := "Source Description:\n"
for _, c := range s.Chunks {
out += fmt.Sprintf("\t%x: %s\n", c.Source, c.Items)
}
return out
}
